AMT transmission and control method thereof

Abstract

The invention belongs to the technical field of transmissions, and discloses an AMT transmission and a control method thereof.The AMT transmission is characterized in that an oil pump assembly is arranged between a transmission shell and a front end cover, a closed cavity is formed between the transmission shell and the front end cover, and an oil pump oil outlet cavity is formed in the closed cavity; an oil duct connected with the oil pump oil outlet cavity is formed in the top of the closed cavity; a movable cavity is arranged on the closed cavity, a bypass valve is arranged in the movable cavity, and a bypass valve air inlet hole is formed in the end part of the movable cavity; a movable hole connected with the oil duct is formed in the transmission shell, one end of the movable hole is connected with the movable cavity, and the other end of the movable hole is connected with an oil storage cavity. And an oil drainage port is reserved between the oil storage cavity and the movable hole. A part of lubricating oil can be controlled to enter the oil storage cavity to be stored and not participate in lubrication of the inner cavity of the transmission in real time through an electric control pneumatic control mode, or oil in the oil storage cavity enters the inner cavity of the transmission through the oil drainage port to participate in lubrication, the lubricating oil amount of the transmission under different working conditions is optimized, and the comprehensive transmission efficiency of the transmission is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of transmissions, and particularly relates to an AMT transmission and a control method thereof. Background Art

[0002] Competition in the automotive industry chain is becoming increasingly fierce, and the performance requirements for automotive transmissions are also getting higher and higher. To improve the transmission efficiency of transmissions, manufacturers have taken various measures such as improving gear accuracy, enhancing tooth surface roughness, using high-precision bearings, and improving the viscosity of lubricating oil. These measures have a certain effect on improving the transmission efficiency, but they also bring an increase in the manufacturing cost of transmissions. Research shows that the higher the viscosity of the lubricating oil in the transmission, the higher the oil level, and the faster the gear running speed, the greater the resistance generated by the gear running, and the lower the transmission efficiency of the transmission. Moreover, under different load conditions of the transmission, the actual required lubricating oil volume is different.

[0003] The Chinese patent publication number is CN113007332A, and the name of the patent application is a transmission lubrication and cooling system. This system uses oil pump pressure lubrication and realizes the lubrication of each lubrication point above the three intermediate shafts of the transmission through the combination of the housing oil passage and the oil pipe. At the same time, a strong cooling interface is reserved at the beginning of the oil circuit, and an external forced cooling system can be connected to control the transmission oil temperature within a reasonable range and extend the service life of the oil product and the transmission. This patent application cannot achieve the control of the lubricating oil volume participating in different working conditions of the transmission and cannot play the role of improving the transmission efficiency of the transmission by controlling the lubricating oil volume. Summary of the Invention

[0004] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide an AMT transmission and a control method thereof. By setting a bypass valve and an oil storage cavity in the forced lubricating oil circuit of the AMT transmission, and controlling the bypass valve to be in different positions according to the working conditions of the transmission in real time, so that a part of the lubricating oil enters the oil storage cavity and does not participate in lubrication or enters the inner cavity of the transmission to participate in lubrication, optimizing the lubricating oil volume of the transmission under different working conditions, and improving the comprehensive transmission efficiency of the transmission.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: In a first aspect, the present invention provides an AMT transmission, comprising: a transmission housing, on which a front end cover is mounted; an oil pump assembly is installed between the transmission housing and the front end cover, and a closed cavity is provided, and an oil pump oil outlet cavity is provided in the closed cavity; an oil passage connected to the oil pump oil outlet cavity is opened at the top of the closed cavity; an activity cavity is provided above the closed cavity, a bypass valve is arranged in the activity cavity, the bypass valve comprises a core shaft, and the core shaft comprises a front end shaft; a bypass valve air inlet hole is opened at the end of the activity cavity; an activity hole connected to the oil passage is opened on the transmission housing, one end of the activity hole is connected to the activity cavity, and the other end is connected to an oil storage cavity; a return spring and a spring retaining piece are sleeved on the front end shaft, and the spring retaining piece is arranged between the return spring and the activity hole; a rear end shaft connected to the front end shaft is movably arranged in the activity hole; an annular groove is opened on the rear end shaft; an oil drain port is left between the oil storage cavity and the activity hole.

[0006] Optionally, a first shaft and a second shaft are arranged in the transmission housing, and the first shaft and the second shaft are coaxially arranged; the first shaft passes through the transmission housing and the front end cover, and an oil passage hole is opened at the closed cavity between the transmission housing and the front end cover of the first shaft, and the oil passage hole is communicated with the oil pump oil outlet cavity, and an axial center oil passage is arranged inside the first shaft and the second shaft, and the axial center oil passage is communicated with the oil passage hole.

[0007] Optionally, the front end cover is mounted on one side of the first shaft protruding from the transmission housing.

[0008] Optionally, a piston is arranged at one end of the front end shaft close to the bypass valve air inlet hole.

[0009] Optionally, a sealing ring is sleeved on the piston.

[0010] Optionally, the transmission is provided with a normally closed two-position three-way solenoid valve, and the normally closed two-position three-way solenoid valve is communicated with the bypass valve air inlet hole.

[0011] Optionally, a spring limit ring is sleeved on the end of the front end shaft close to the piston, and the spring limit ring is fixedly connected to the front end shaft; two end faces of the return spring are respectively abutted against the spring limit ring and the spring retaining piece.

[0012] Optionally, a sealing ring is arranged on one side of the activity hole close to the front end shaft, and the sealing ring is clamped on the front end face of the activity hole.

[0013] Optionally, the bottom plate of the oil storage cavity is arranged between the top and the bottom of the hole wall of the activity hole.

[0014] In a second aspect, the present invention provides a control method for the AMT transmission described above, comprising the following steps: When the transmission needs to reduce the lubricating oil volume, air is introduced into the bypass valve air inlet hole. The piston and the mandrel are pushed by air pressure to move away from the air inlet hole. Meanwhile, the return spring is compressed until the rear end shaft of the mandrel blocks the oil drain port and makes the annular groove communicate with the oil storage cavity. The lubricating oil in the oil outlet cavity of the oil pump enters the oil storage cavity through the oil passage and the annular groove under the action of oil pressure, and the amount of lubricating oil participating in lubrication in the transmission cavity is reduced. When the transmission needs to increase the lubricating oil volume, the air supply to the bypass valve air inlet hole is stopped. The return spring rebounds and drives the mandrel to move to one side of the bypass valve air inlet hole, and the oil drain port opens. The lubricating oil stored in the oil storage cavity leaks out from the oil drain port and enters the transmission cavity, and the amount of lubricating oil participating in lubrication in the transmission increases.

[0015] Compared with the prior art, the present invention has the following beneficial effects: An AMT transmission and its control method provided by the present invention can control the amount of lubricating oil participating in splash lubrication inside the transmission under different working conditions to improve the transmission efficiency of the transmission. The transmission of the present invention adopts a dual lubrication method of splash plus forced lubrication. After the lubricating oil in the transmission is sucked into the oil pump assembly and pressurized, it enters the bypass valve in the oil outlet cavity of the oil pump. By controlling the mandrel of the bypass valve to be in different positions, a part of the oil in the oil outlet cavity of the oil pump can be controlled to enter and be stored in the oil storage cavity, thereby reducing the amount of lubricating oil participating in splash lubrication in the transmission cavity and improving the transmission efficiency of the transmission under specific working conditions.

[0016] The transmission of the present invention optimizes the lubricating oil volume under different working conditions to improve the transmission efficiency when the transmission is working in the high gear range, and at the same time ensures sufficient lubrication when working in the low gear range, thereby improving the comprehensive transmission efficiency and performance of the transmission. Description of the Drawings

[0017] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure of the present invention in any way. Additionally, the shapes and proportional dimensions of the components in the drawings are only schematic for helping the understanding of the present invention and do not specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings: Figure 1 is a partial schematic diagram of the internal components of the transmission of the present invention; Figure 2 is a schematic diagram of the bypass valve of the transmission of the present invention in the first position; Figure 3 is a schematic diagram of the bypass valve of the transmission of the present invention in the second position; Figure 4 is a control connection diagram of the TCU, solenoid valve and bypass valve of the transmission of the present invention; Figure 5 is a control logic diagram of the TCU of the transmission of the present invention for the bypass valve; Among them, 1. Transmission housing; 2. Front end cover; 3. Oil pump assembly; 4. Bypass valve; 5. Oil storage chamber; 6. Lubricating oil pipe; 7. Axial oil passage; 8. First shaft; 81. Oil passage hole; 9. Second shaft; 10. Intermediate shaft; 11. Overflow hole; 12. Oil pump outlet chamber; 13. Piston; 14. Return spring; 15. Spring limit ring; 16. Bypass valve intake hole; 17. Spring retaining plate; 18. Core shaft; 181. Front end shaft; 182. Rear end shaft; 183. Movable hole; 19. Sealing ring; 20. Ring groove; 21. Oil passage; 22. Oil drain port; 23. Sealing ring; Y1. Two-position three-way solenoid valve; TCU. Transmission control unit. Detailed implementation manners

[0018] In order to enable those skilled in the art of the present technology to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

[0020] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention.

[0021] When an element is referred to as being "disposed on" another element, it can be directly on the other element or there can be intervening elements. When an element is considered to be "connected" to another element, it can be directly connected to the other element or intervening elements may be present. The terms "vertical", "horizontal", "left", "right", and similar expressions used herein are for illustrative purposes only and do not denote the only embodiments. When the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0022] It should be noted that like reference numerals and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. In the description of the present invention, it is to be understood that the terms "comprising" and "including" indicate the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or their groups.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing particular embodiments only and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0024] The present invention will be described in detail below with reference to the accompanying drawings.

[0025] As Figure 1As shown in the figure, an AMT transmission of the present invention includes: a transmission housing 1, on which a front end cover 2 is installed; an oil pump assembly 3 is installed between the transmission housing 1 and the front end cover 2 and a closed cavity is provided, and an oil pump oil outlet cavity 12 is provided in the closed cavity; an oil passage 21 connected to the oil pump oil outlet cavity 12 is opened at the top of the closed cavity; a movable cavity is provided above the closed cavity, and a bypass valve air inlet hole 16 is opened at the end of the movable cavity; a bypass valve 4 is movably arranged in the movable cavity, and the bypass valve 4 includes a core shaft 18, and the core shaft 18 includes a front end shaft 181; a movable hole 183 connected to the oil passage 21 is opened on the transmission housing 1, one end of the movable hole 183 is connected to the movable cavity, and the other end is connected to an oil storage cavity 5; a return spring 14 and a spring retainer 17 are sleeved on the front end shaft 181, and the spring retainer 17 is arranged between the return spring 14 and the movable hole 183; a rear end shaft 182 connected to the front end shaft 181 is movably arranged in the movable hole 183; a ring groove 20 is opened on the rear end shaft 182; an oil drain port 22 is left between the oil storage cavity 5 and the movable hole 183; an overflow hole 11 is provided on the inner wall of the oil storage cavity 5 on the side away from the movable hole 183.

[0026] The length of the ring groove 20 in the axial direction of the rear end shaft 182 is greater than the sum of the width of the oil passage 21 and the axial moving distance of the core shaft 18. So that the ring groove 20 is always communicated with the oil passage 21.

[0027] The transmission is provided with a normally closed two-way three-way solenoid valve Y1, and the normally closed two-way three-way solenoid valve Y1 is communicated with the bypass valve air inlet hole 16.

[0028] When an AMT transmission of the present invention is in use, it includes the following steps: When the transmission needs to reduce the amount of lubricating oil, the transmission control unit TCU turns on and controls the two-way three-way solenoid valve Y1 of the bypass valve 4, the two-way three-way solenoid valve Y1 is energized and opened, the air supply air path is connected, the bypass valve air inlet hole 16 intakes air, the piston 13 and the core shaft 18 are pushed by the air pressure to move in the direction away from the bypass valve air inlet hole 16, and at the same time the return spring 14 is compressed until the rear end shaft 182 of the core shaft 18 blocks the oil drain port 22 and makes the ring groove 20 communicate with the oil storage cavity 5; the lubricating oil in the oil pump oil outlet cavity 12 enters the oil storage cavity 5 through the oil passage 21 and the ring groove 20 and is stored, and the amount of oil participating in lubrication in the transmission cavity is reduced; When the transmission needs to increase the lubricating oil volume, the transmission control unit TCU disconnects and controls the two-position three-way solenoid valve Y1 of the bypass valve 4. The two-position three-way solenoid valve Y1 loses power, the air supply air path is closed, the air intake hole 16 of the bypass valve is stopped from being ventilated, the return spring 14 rebounds and drives the mandrel 18 to move to one side of the air intake hole 16 of the bypass valve, the oil drain port 22 is opened, and the lubricating oil stored in the oil storage cavity 5 leaks out from the oil drain port 22 and enters the transmission cavity, increasing the amount of oil participating in lubrication in the transmission.

[0029] An AMT transmission and its control method provided by the present invention can control the amount of oil participating in splash lubrication inside the transmission under different working conditions to improve the transmission efficiency of the transmission. The transmission of the present invention adopts a dual lubrication method of splash plus forced lubrication. After the lubricating oil in the transmission is sucked into the oil pump assembly 3 and pressurized, it enters the bypass valve 4 in the oil outlet cavity 12 of the oil pump. By controlling the mandrel 18 of the bypass valve 4 to be in different positions, a part of the oil in the oil outlet cavity 12 of the oil pump can be controlled to enter and be stored in the oil storage cavity 5, thereby reducing the amount of oil participating in splash lubrication in the transmission cavity and improving the transmission efficiency of the transmission under specific working conditions.

[0030] The transmission of the present invention optimizes the lubricating oil volume of the transmission under different working conditions to improve the transmission efficiency when the transmission is working in the high gear range, and at the same time ensures sufficient lubrication when working in the low gear range, thereby improving the comprehensive transmission efficiency and performance of the transmission.

[0031] Embodiment 1 See Figures 1 to 3 , the transmission provided by the present invention includes: a transmission housing 1, a front end cover 2, an oil pump assembly 3, a bypass valve 4, a first shaft 8, a second shaft 9, and an intermediate shaft 10.

[0032] The front end cover 2 is installed on one side of the first shaft 8 extending out of the transmission housing 1. A through hole is provided on the front end cover 2, and the first shaft 8 passes through the through hole of the front end cover 2.

[0033] The oil pump assembly 3 is installed at one end of the intermediate shaft 10 of the transmission close to the first shaft 8 and is driven by the intermediate shaft 10. One end of the oil pump assembly 3 is connected to the transmission housing 1, and the other end is connected to the front end cover 2.

[0034] An oil outlet cavity 12 is left between the transmission housing 1 and the front end cover 2.

[0035] The oil pump assembly 3 has an oil outlet, and the oil outlet of the oil pump assembly 3 is communicated with the oil outlet cavity 12.

[0036] The bypass valve 4 is installed between the front end cover 2 and the transmission housing 1. The bypass valve 4 is arranged above the first shaft 8.

[0037] Optionally, the top of the front end cover 2 protrudes outward, and there is a top cavity inside the protruding part, and the bypass valve 4 is arranged in the top cavity of the front end cover 2.

[0038] The front end cover 2 is provided with a bypass valve air inlet hole 16 at the end of the bypass valve 4.

[0039] The first shaft 8 is provided with an oil passage hole 81 at the connection with the oil pump oil outlet cavity 12, and the oil passage hole 81 is communicated with the oil pump oil outlet cavity 12. The first shaft 8 and the second shaft 9 have an axial center oil passage 7 inside, and the axial center oil passage 7 is communicated with the oil passage hole 81.

[0040] A lubricating oil pipe 6 is arranged in the transmission housing 1, and the lubricating oil pipe 6 is communicated with the oil pump oil outlet cavity 12.

[0041] The oil pump oil outlet cavity 12 is communicated with the bypass valve 4, the axial center oil passage 7 and the lubricating oil pipe 6.

[0042] The transmission housing 1 is provided with an oil passage 21. The oil passage 21 is communicated with the bypass valve 4.

[0043] After being pressurized by the oil pump, the lubricating oil in the oil pump oil outlet cavity 12 is divided into three paths: One path of oil enters the lubricating oil pipe 6 to spray and lubricate the parts in the transmission. One path of oil enters the axial center oil passage 7 to forcibly lubricate the key parts on the shaft. One path of oil enters the bypass valve 4 through the oil passage 21 on the transmission housing 1.

[0044] The bypass valve air inlet hole 16 is connected with a normally closed two-way three-way solenoid valve Y1, and the normally closed two-way three-way solenoid valve Y1 is communicatively connected with the automatic transmission control unit TCU. The inlet and exhaust of the bypass valve 4 are controlled by the two-way three-way solenoid valve Y1.

[0045] The bypass valve 4 includes a core shaft 18. The core shaft 18 includes a front end shaft 181, the front end of the front end shaft 181 faces the bypass valve air inlet hole 16, and the rear end is connected with a rear end shaft 182.

[0046] A piston 13 is arranged between the front end shaft 181 and the bypass valve air inlet hole 16.

[0047] Optionally, a sealing ring is sleeved outside the piston 13.

[0048] A return spring 14 is sleeved on the front end shaft 181, a spring limit ring 15 is sleeved on the front end of the front end shaft 181, and the spring limit ring 15 is fixedly connected with the front end shaft 181 through a snap ring. One end of the spring limit ring 15 is connected with the return spring 14, and the other end is connected with the snap ring connected to the front end shaft 181.

[0049] Both end faces on two sides of the return spring 14 are respectively abutted against the spring limit ring 15 and the spring retaining piece 17.

[0050] An activity hole 183 is formed in the transmission housing 1, and the rear end shaft 182 passes through the activity hole 183. The rear end shaft 182 is communicated with the oil passage 21.

[0051] A spring retaining piece 17 is sleeved on the end part of the front end shaft 181 close to the rear end shaft 182.

[0052] Optionally, the spring retaining piece 17 is a bowl-shaped sheet metal part. A through hole is formed in the central part of the spring retaining piece 17. The front end shaft 181 passes through the through hole of the spring retaining piece 17. The periphery of the spring retaining piece 17 protrudes from one side of the end face and contacts the transmission housing 1, and the other end face abuts against the return spring 14. The spring retaining piece 17 generates a pre-pressure on the return spring 14.

[0053] A ring groove 20 is formed in the rear end shaft 182. The ring groove 20 can enable the mandrel 18 to always be communicated with the oil passage 21 within the activity range.

[0054] Specifically, the length of the ring groove 20 in the axial direction of the rear end shaft 182 is greater than the sum of the width of the oil passage 21 and the axial movement distance of the mandrel 18.

[0055] An oil storage cavity 5 is formed in the transmission housing 1. An overflow hole 11 is formed in the side wall of the oil storage cavity 5. The oil storage cavity 5 is formed at the top of the transmission housing 1, and the bottom of the oil storage cavity 5 is communicated with the activity hole 183 of the mandrel 18 of the bypass valve 4.

[0056] Specifically, the oil storage cavity 5 is connected to the top of the hole wall of the activity hole 183; the bottom plate of the oil storage cavity 5 is arranged between the top and the bottom of the hole wall of the activity hole 183.

[0057] Optionally, the groove surface of the ring groove 20 is a conical surface.

[0058] A drain port 22 is left between the bottom plate of the oil storage cavity 5 and the bottom of the hole wall of the activity hole 183.

[0059] A sealing ring 19 is arranged on one side of the activity hole 183 close to the front end shaft 181, and the sealing ring 19 is clamped on the front end face of the activity hole 183.

[0060] The sealing ring 19 is in sealing fit with the rear end shaft 182, and can prevent the lubricating oil entering the bypass valve from entering the cavity at the top of the front end cover where the front end shaft 181 is located.

[0061] By controlling the position of the mandrel 18 of the bypass valve 4, the opening and closing of the drain port 22 are controlled.

[0062] When the rear end shaft 182 of the mandrel 18 is pushed until it contacts the bottom plate of the oil storage cavity 5, while the rear end shaft 182 blocks the oil drain port 22, the annular groove 20 communicates with the oil storage cavity 5.

[0063] Embodiment 2 When the two-way three-way solenoid valve Y1 loses power, there is no gas entering the bypass valve 4. In the original state where the bypass valve 4 is not ventilated, under the pre-pressure of the return spring 14, the mandrel 18 presses against the piston 13 and is in the leftmost position, which is the first position of the bypass valve 4, as Figure 2 shown.

[0064] At this time, the annular groove 20 on the mandrel 18 does not communicate with the oil storage cavity 5, and the lubricating oil in the oil outlet cavity 12 of the oil pump cannot enter the oil storage cavity 5 through the oil passage 21 and the annular groove 20.

[0065] The oil drain port 22 is in an open state at this time, and the lubricating oil in the oil storage cavity 5 will flow back into the transmission cavity to participate in lubrication, and there is no lubricating oil stored in the oil storage cavity 5. The transmission operates with the normal lubricating oil volume.

[0066] When the two-way three-way solenoid valve Y1 is powered on, the air inlet hole 16 of the bypass valve opens, compressed air enters the bypass valve 4, the piston 13 and the mandrel 18 are pushed by the compressed air, the return spring 14 is compressed, and they move together to the side away from the air inlet hole 16 of the bypass valve until the mandrel 18 abuts against the mandrel 18 limiting end face on the transmission housing 1, and the oil drain port 22 is filled by the rear end shaft 182 and enters the closed state, that is, the bypass valve 4 is in the second position, as Figure 3 shown. At this time, the annular groove 20 on the mandrel 18 communicates with the oil storage cavity 5, and a part of the lubricating oil in the oil outlet cavity 12 of the oil pump will continuously enter the oil storage cavity 5 through the oil passage 21 and the annular groove 20 until the lubricating oil level in the oil storage cavity 5 reaches the position of the overflow hole 11, and the lubricating oil above the horizontal position of the overflow hole 11 flows back into the transmission inner cavity, and the part of the lubricating oil below the horizontal position of the overflow hole 11 is stored in the oil storage cavity 5.

[0067] The amount of lubricating oil participating in lubrication in the transmission decreases, the oil level height decreases, the running resistance of the gears decreases, and accordingly the transmission efficiency is improved.

[0068] In this embodiment, by innovatively setting the width of the annular groove 20, the relative position of the oil passage 21 and the annular groove 20, and the fit between the mandrel 18 and the transmission housing 1, it is ensured that regardless of whether the bypass valve 4 is in Figure 2 the first position shown in Figure 3 and the second position shown in

[0069] During the operation of the transmission, when the transmission control unit TCU receives the transmission input and output speed information collected by the speed sensors, it determines whether the transmission is in a high-speed and light-load operation state.

[0070] When the transmission is in a high-speed and light-load operation state, the transmission is in the high gear range for operation, and the working gears rotate at high speed, generating a large oil churning resistance. At this time, the transmission control unit TCU energizes the solenoid valve Y1 to open the intake passage of the bypass valve 4, causing the bypass valve 4 to enter the second position. A part of the lubricating oil will be transported and stored in the oil storage cavity 5 at the top of the transmission housing 1. The total amount of oil in the transmission cavity decreases, the oil level inside the transmission drops, and the oil churning resistance generated by the high-speed rotation of the gears decreases, improving the transmission efficiency when the transmission is in the high gear range.

[0071] When the vehicle is operating in a heavy-load state, the transmission is in the low gear range for operation, and the working gears rotate at a relatively low speed and bear large stresses at the same time. At this time, the transmission control unit TCU de-energizes the solenoid valve Y1 to close the intake passage of the bypass valve 4, causing the bypass valve 4 to enter the first position, cutting off the passage for the lubricating oil to enter the top oil sump. The oil drain port 22 provided at the bottom of the oil sump opens, and the lubricating oil stored in the top oil sump of the transmission flows back to the transmission inner cavity under the action of gravity through the oil drain port 22 at the bottom of the oil sump to continue participating in splash lubrication, ensuring sufficient and good lubrication when the transmission is in the low gear range and improving the working reliability of the transmission.

[0072] In the above embodiments, the equipment elements involved, unless otherwise specified, are all conventional equipment elements. The structural setting methods, working methods, or control methods involved, unless otherwise specified, are all conventional setting methods, working methods, or control methods in this field.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solutions of the present invention should be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. An AMT transmission, characterized in that: include: A transmission housing (1), wherein a front end cover (2) is mounted on the transmission housing (1); an oil pump assembly (3) is mounted between the transmission housing (1) and the front end cover (2) and a closed cavity is provided, wherein the closed cavity has an oil pump outlet cavity (12); an oil passage (21) connected to the oil pump outlet cavity (12) is provided at the top of the closed cavity; an active cavity is provided above the closed cavity, wherein a bypass valve (4) is provided in the active cavity, wherein the bypass valve (4) comprises a core shaft (18), wherein the core shaft (18) comprises a front end shaft (181); an air inlet hole (16) for the bypass valve is provided at the end of the active cavity; (1) is provided with a movable hole (183) connected to the oil passage (21), one end of the movable hole (183) is connected to the movable chamber, and the other end is connected to the oil storage chamber (5); a return spring (14) and a spring stopper (17) are sleeved on the front end shaft (181), and the spring stopper (17) is arranged between the return spring (14) and the movable hole (183); a rear end shaft (182) connected to the front end shaft (181) is movably arranged in the movable hole (183); an annular groove (20) is provided on the rear end shaft (182); and an oil drain port (22) is reserved between the oil storage chamber (5) and the movable hole (183).

2. The AMT transmission according to claim 1, characterized in that: A first shaft (8) and a second shaft (9) are arranged in the transmission housing (1), and the first shaft (8) and the second shaft (9) are coaxially arranged; the first shaft (8) passes through the transmission housing (1) and the front end cover (2); the first shaft (8) is provided with an oil passage hole (81) in a closed cavity between the transmission housing (1) and the front end cover (2); the oil passage hole (81) is connected to the oil pump outlet cavity (12); the first shaft (8) and the second shaft (9) have axial oil passages (7) inside, and the axial oil passages (7) are connected to the oil passage hole (81).

3. The AMT transmission according to claim 2, characterized in that: The front end cover (2) is mounted on one side of a shaft (8) extending from the transmission housing (1).

4. The AMT transmission according to claim 1, characterized in that: A piston (13) is provided at one end of the front end shaft (181) close to the bypass valve air inlet hole (16).

5. The AMT transmission according to claim 4, characterized in that: A sealing ring (23) is sleeved on the piston (13).

6. The AMT transmission according to claim 1, characterized in that: The transmission is provided with a normally closed two-position three-way solenoid valve (Y1), and the normally closed two-position three-way solenoid valve (Y1) is connected to the bypass valve air inlet hole (16).

7. The AMT transmission according to claim 1, characterized in that: A spring limiting ring (15) is sleeved on the end of the front end shaft (181) close to the piston (13), and the spring limiting ring (15) is fixedly connected to the front end shaft (181); the end surfaces on both sides of the return spring (14) respectively abut against the spring limiting ring (15) and the spring stopper (17).

8. The AMT transmission according to claim 1, characterized in that: A sealing ring (19) is provided on one side of the movable hole (183) close to the front end shaft (181), and the sealing ring (19) is clamped on the front end surface of the movable hole (183).

9. The AMT transmission according to claim 1, characterized in that: The bottom plate of the oil storage chamber (5) is arranged between the top and bottom of the hole wall of the movable hole (183).

10. The control method of an AMT transmission according to any one of claims 1 to 9, characterized in that: The following steps are involved: When the transmission needs to reduce the amount of lubricating oil, the bypass valve air inlet hole (16) is ventilated, and the piston (13) and the core shaft (18) are pushed by the air pressure to move away from the air inlet hole (16), and the return spring (14) is compressed until the rear end shaft (182) of the core shaft (18) blocks the oil drain port (22) and connects the annular groove (20) with the oil storage chamber (5); the lubricating oil in the oil pump outlet chamber (12) enters the oil storage chamber (5) through the oil passage (21) and the annular groove (20) under the action of the oil pressure, and the amount of oil involved in lubrication in the transmission chamber is reduced; When the transmission needs to increase the amount of lubricating oil, ventilation to the bypass valve air inlet hole (16) is stopped, the return spring (14) rebounds to drive the core shaft (18) to move to one side of the bypass valve air inlet hole (16), the oil drain port (22) is opened, and the lubricating oil stored in the oil storage chamber (5) leaks out from the oil drain port (22) into the transmission cavity, thereby increasing the amount of oil involved in lubrication in the transmission.

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